[Federal Register Volume 62, Number 17 (Monday, January 27, 1997)]
[Proposed Rules]
[Pages 3832-3834]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1825]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-175-AD]
RIN 2120-AA64
Airworthiness Directives; Short Brothers Model SD3-30 and SD3-60
Series Airplanes Equipped with Fire Fighting Enterprises (U.K.) Ltd.
Fire Extinguishers
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to all Shorts Model SD3-30 and SD3-60
series airplanes equipped with certain fire extinguishers. This
proposal would require replacement of the covers for fire extinguisher
adapter assemblies that are installed on certain bulkheads with new
covers that swivel to lock the extinguishers in place; and replacement
of nozzles and triggers on these fire extinguishers with better fitting
nozzles and stronger triggers. It also would require the installation
of new fire extinguisher point placards and a revision of the Airplane
Flight Manual to instruct the flight crew in the use of the new covers
for these adapter assemblies. This proposal is prompted by reports that
these fire extinguishers are not discharging properly because they do
not fit correctly with the adapter, and that triggers on these
extinguishers are failing. The actions specified by the proposed AD are
intended to ensure that, in the event of fire in the baggage bay,
extinguishing agent is properly distributed within this area, and
portable extinguishers operate properly; and to prevent injury to crew
and passengers when a portable extinguisher is discharged.
DATES: Comments must be received by March 7, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-175-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
The service information referenced in the proposed rule may be
obtained from Short Brothers PLC, 2011 Crystal Drive, Suite 713,
Arlington, Virginia 22202-3719. This information may be examined at the
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Greg Dunn, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2799; fax (206) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications shall identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 96-NM-175-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 96-NM-175-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The FAA has received reports indicating that certain portable cabin
fire extinguishers, manufactured by Fire Fighting Enterprises Ltd. and
carried onboard all Shorts Model SD3-30 and SD3-60 series airplanes,
may not work properly when installed on bulkheads separating the
passenger cabin from the
[[Page 3833]]
aft and/or forward baggage bays. Because the nozzle of the extinguisher
and the adapter do not fit together correctly, the extinguishing agent
is ``blown back'' into the passenger cabin. This condition, if not
corrected, could prevent adequate distribution of fire extinguishing
agent within the baggage bay, and could cause injury to crew and
passengers.
The FAA also has received reports indicating that triggers on these
fire extinguishers have failed because the operator did not lift the
safety catch before squeezing the trigger; this caused the trigger to
break at the neck of the actuating tang. This condition, if not
corrected, could make the extinguisher unserviceable and, if broken
during operation, could cause the extinguisher to fail, or cause a loss
in the ability to control or stop discharge of the extinguishing agent.
Explanation of Relevant Service Information
Short Brothers has issued Shorts Service Bulletin SD330-26-14,
dated September 1994 (for Model SD3-30 series airplanes); and Service
Bulletin SD360-26-11, dated July 1994 (for Model SD3-60 series
airplanes). These service bulletins describe procedures for replacing
the covers of the fire extinguisher adapter assemblies installed on
bulkheads between the passenger cabin and baggage bays with new covers
that swivel and lock the extinguishers in place. These service
bulletins also describe procedures for installing new fire extinguisher
point placards and revising the Airplane Flight Manual (AFM) to include
instructions for the flight crew about using the new covers with the
fire extinguishers.
Fire Fighting Enterprises (U.K.) Ltd. has issued Service Bulletin
26-107, Revision 1, dated November 2, 1992, which describes procedures
for replacing the nozzles on portable cabin fire extinguishers having
part number (P/N) BA51012SR-3 and BA51012SR. The replacement nozzles
are chamfered, and fit more closely in the ``O'' ring of the bulkhead
adapter; this will prevent ``blow back'' of the extinguishing agent
when the extinguisher is used.
In addition, Fire Fighting Enterprises (U.K.) Ltd. has issued
Service Bulletin 26-108, dated September 1992, which describes
procedures for replacing triggers on the discharge head assemblies of
fire extinguishers carried on Shorts Model SD3-30 and SD3-60 series
airplanes. The replacement trigger is manufactured from an improved and
stronger material, and the radii around the neck of the actuating tang
has been increased for additional strength.
Type Certification of Airplanes
These airplane models are manufactured in the United Kingdom and
type certificated for operation in the United States under the
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR
21.29) and the applicable bilateral airworthiness agreement.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other products of this same type design, the
proposed AD would require replacement of covers on fire extinguisher
adapter assemblies on bulkheads between the passenger cabin and baggage
bays with new covers that swivel and lock extinguishers in place. It
would also require replacement of nozzles on these extinguishers with
chamfered nozzles that fit better with these adapters; and replacement
of triggers on these extinguishers with triggers made from improved and
stronger materials.
Additionally, this proposed AD would require installation of new
fire extinguisher point placards, and a revision of the Limitations
Section of the FAA-approved AFM to include instructions for the flight
crew about using the new adapter assembly covers with the fire
extinguishers.
These actions would be required to be accomplished in accordance
with the applicable service bulletins described previously.
Cost Impact
The FAA estimates that 50 Model SD3-30 series airplanes of U.S.
registry would be affected by this proposed AD. For these airplanes, it
would take approximately 9 work hours per airplane to accomplish the
proposed actions on airplanes with only a forward baggage bay, and 14
work hours per airplane to accomplish the proposed actions on airplanes
with forward and aft baggage bays. The average labor rate is $60 per
work hour. Required parts would cost approximately $281 per airplane.
Based on these figures, the cost impact of the proposed AD on U.S.
operators of Model SD3-30 series airplanes is estimated to be between
$41,050 and $56,050, or between $821 and $1,121 per airplane.
The FAA estimates that 72 Model SD3-60 series airplanes of U.S.
registry would be affected by this proposed AD. For these airplanes, it
would take approximately 12 work hours per airplane to accomplish the
proposed actions, at an average labor rate of $60 per work hour.
Required parts would cost approximately $281 per airplane. Based on
these figures, the cost impact of the proposed AD on U.S. operators of
Model SD3-60 series airplanes is estimated to be $72,072, or $1,001 per
airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed requirements
of this AD action, and that no operator would accomplish those actions
in the future if this AD were not adopted.
Regulatory Impact
The regulations proposed herein would not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the DOT
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);
and (3) if promulgated, will not have a significant economic impact,
positive or negative, on a substantial number of small entities under
the criteria of the Regulatory Flexibility Act. A copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
[[Page 3834]]
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Short Brothers, PLC: Docket 96-NM-175-AD.
Applicability: All Model SD3-30 and SD3-60 series airplanes
equipped with fire extinguishers manufactured by Fire Fighting
Enterprises (U.K.) Ltd.; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (d) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it.
Compliance: Required as indicated, unless accomplished
previously.
To ensure that, in the event of fire, extinguishing agent is
properly distributed within the baggage bays and portable
extinguishers operate properly; and to prevent injury to crew and
passengers, accomplish the following:
(a) Within 6 months after the effective date of this AD, install
a new cover on each fire extinguisher adapter assembly on bulkheads
between the passenger cabin and aft and/or forward baggage bay, in
accordance with Shorts Service Bulletin SD330-26-14, dated September
1994 (for Shorts Model SD3-30 series airplanes), or Shorts Service
Bulletin SD360-26-11, dated July 1994 (for Shorts Model SD3-60
series airplanes), as applicable.
(b) Prior to further flight after accomplishing the actions
required by paragraph (a) of this AD, accomplish both paragraphs
(b)(1) and (b)(2) of this AD:
(1) Install new fire extinguisher point placards, in accordance
with Shorts Service Bulletin SD330-26-14, dated September 1994 (for
Shorts Model SD3-30 series airplanes), or Shorts Service Bulletin
SD360-26-11, dated July 1994 (for Shorts Model SD3-60 series
airplanes), as applicable. And
(2) Revise the Limitations Section of the FAA-approved Airplane
Flight Manual (AFM), in accordance with Note 1 of Paragraph 1.C. of
Shorts Service Bulletin SD330-26-14, dated September 1994 (for
Shorts Model SD3-30 series airplanes), or Shorts Service Bulletin
SD360-26-11, dated July 1994 (for Shorts Model SD3-60 series
airplanes), as applicable.
(c) For airplanes equipped with fire extinguishers having part
number (P/N) BA51012SR-3 or BA51012SR: Within 6 months after the
effective date of this AD, accomplish either paragraph (c)(1) or
(c)(2) of this AD:
(1) Install a chamfered nozzle on the discharge head assembly of
each fire extinguisher by replacing the discharge head assembly with
a new discharge head assembly, having P/N BA22988-3, in accordance
with Fire Fighting Enterprises (U.K.) Ltd. Service Bulletin 26-107,
Revision 1, dated November 2, 1992. Or
(2) Replace the trigger on the discharge head assembly of each
fire extinguisher with a new trigger, in accordance with Fire
Fighting Enterprises (U.K.) Ltd. Service Bulletin 26-108, dated
September 1992. After replacement, install a chamfered nozzle on the
discharge head assembly of each fire extinguisher by reworking the
discharge head assembly in accordance with Fire Fighting Enterprises
(U.K.) Ltd. Service Bulletin 26-107, Revision 1, dated November 2,
1992
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Standardization Branch, ANM-113,
FAA, Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager,
Standardization Branch, ANM-113.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(e) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
Issued in Renton, Washington, on January 17, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-1825 Filed 1-24-97; 8:45 am]
BILLING CODE 4910-13-U
